Slow startup because of low entropy for PRNG

[ago1024]

Describe the bug

b3607a7 changed JCEEncryptor to use SecureRandom.getInstanceStrong(). In OpenJDK on Unix systems this is NativePRNG.Blocking which will stall if the kernel does not provide enough entropy.

We've noticed this behaviour on our CI systems where EclipseLink 2.714 startup would stall the tests.

   java.lang.Thread.State: RUNNABLE
        at java.io.FileInputStream.readBytes(java.base@11.0.22/Native Method)
        at java.io.FileInputStream.read(java.base@11.0.22/FileInputStream.java:279)
        at java.io.FilterInputStream.read(java.base@11.0.22/FilterInputStream.java:133)
        at sun.security.provider.NativePRNG$RandomIO.readFully(java.base@11.0.22/NativePRNG.java:424)
        at sun.security.provider.NativePRNG$RandomIO.ensureBufferValid(java.base@11.0.22/NativePRNG.java:526)
        at sun.security.provider.NativePRNG$RandomIO.implNextBytes(java.base@11.0.22/NativePRNG.java:545)
        - locked <0x00000000fcca7318> (a java.lang.Object)
        at sun.security.provider.NativePRNG$Blocking.engineNextBytes(java.base@11.0.22/NativePRNG.java:268)
        at java.security.SecureRandom.nextBytes(java.base@11.0.22/SecureRandom.java:751)
        at org.eclipse.persistence.internal.security.JCEEncryptor$Synergizer.getIvGCM(JCEEncryptor.java:243)
        at org.eclipse.persistence.internal.security.JCEEncryptor$Synergizer.access$4(JCEEncryptor.java:235)
        at org.eclipse.persistence.internal.security.JCEEncryptor.encryptPassword(JCEEncryptor.java:102)
        - locked <0x00000000ff7ea7e8> (a org.eclipse.persistence.internal.security.JCEEncryptor)
        at org.eclipse.persistence.sessions.DatasourceLogin.setPassword(DatasourceLogin.java:416)
        at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.updateLogins(EntityManagerSetupImpl.java:2483)
        at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.updateSession(EntityManagerSetupImpl.java:2806)
        at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:751)
        at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.getAbstractSession(EntityManagerFactoryDelegate.java:222)
        - locked <0x00000000fcd757a8> (a org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate)
        at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.createEntityManagerImpl(EntityManagerFactoryDelegate.java:330)
        at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManagerImpl(EntityManagerFactoryImpl.java:350)
        at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:313)

To Reproduce
Steps/resources to reproduce the behavior:

• EclipseLink version 2.7.14
• Java/JDK version JDK8/11/17/21

Expected behavior
The codepath should use the nonblocking PRNG to avoid a blocked startup because of low entropy.